Engman/GettyIn 'Game Change' (below), Sarah Palin is portrayed as having an erratic personality.

The gossipy new campaign book that has the political world buzzing portrays Sarah Palin not just as an ignoramus who believed Saddam Hussein was behind 9/11 but also as possibly mentally unstable.

"Game Change," the 2008 deconstruction, says the stress of vaulting onto the national stage caused Palin to have wild mood swings.

"One minute, Palin would be her perky self; the next she would fall into a strange blue funk," the authors write.

The morning of her ill-fated CBS interview with Katie Couric, Palin - "her eyes glassy and dead" - was unresponsive to attempts to prep her as she was being made up.

"As they were about to set off to meet Couric, Palin announced 'I hate this makeup' - smearing it off her face, messing up her hair, complaining she looked fat," the book relates.

Palin went on to give answers to Couric that were so incoherent the interview permanently damaged her.

Palin went into a tailspin. She stopped eating or sleeping, and drank only a half a can of diet soda a day, recounts the book written by John Heilemann of New York magazine and Mark Halperin of Time magazine.

"When her aides tried to quiz her she would routinely shut down - chin on her chest, arms folded, eyes cast to the floor, speechless and motionless, lost in what those around her described as a kind of catatonic stupor," the book says.

"If I had known everything I know now, I would not have done this," the book quotes Palin as saying.

She talked often about her baby, Trig, who spent most of the time in Alaska, and some John McCain aides thought she might be suffering postpartum depression.

When the campaign took her to Arizona to prep for the veep debate, McCain's staff made sure a doctor friend was on hand "to observe her," the book says.

Palin's spokeswoman Meg Stapleton has dismissed the book's allegations as inaccurate gossip from people who weren't there.

"The governor's descriptions of these events are found in her book, 'Going Rogue.' Her descriptions are accurate," Stapleton said in a statement Sunday night to 60 Minutes."  "She was there. These reporters were not."

"Game Change," which features priceless images like Rudy Giuliani, John McCain and Mike Huckabee in a line at a pre-debate urinal, making fun of the absent Mitt Romney - also up contains many other revelations:

The book says aides feared Bill Clinton was jeopardizing his wife's run by having an affair in 2006. The book says a trio of Hillary's top aides formed "a war room within a war room" to counter gossip about her husband and were able to discount all philandering rumors but one.